Lecture 1 - Large Intestine Flashcards
Antibiotic associated diarrhea is not the same as antibiotic associated colitis.
True colitis is nearly always a result of infection with c. diff.
If a patient comes in w/ diarrhea OR gets diarrhea in the first 2 days, we typically don’t consider C diff.
Remember, diarrhea acquired on day three or after, we should consider C diff.
Fluoroquinolones
Ampicillin
Clindamycin
Cephalosporins (3rd gen)
Most common causative agents of C diff
however, almost all have been implicated
Watery, greenish, foul smelling stool that may contain mucus
Abd cramping
Mild leukocytosis on CBC (<15,000)
Mild-moderate antibiotic associated colitis
Profuse diarrhea and fever (<101.3)
Hypoalbuminemia (serum albumin < 3g)
PLUS 1 of:
Abd pain w/ diffuse TTP
OR
leukocytosis on CBC >15,000
Severe disease
Antibiotic associated colitis
What are the reqs for a SEVERE version of antiobiotic associated colitis?
- Profuse diarrhea/fever (<101.3)
- Hypoalbuminemia (<3g/dL)
AND at least one of the following…
3a. Abd pain w/ diffuse TTP
3b. Leukocytosis on CBC > 15000
Admission to ICU HOTN (w/ or w/o vasopressors) Fever > 101.3 Ileus of significant/visible abd distension Mental status changes WBC>35,000 Serum > 2.2 End organ failure
FULMINANT antibiotic associated colitis
Result of severe inflammation
Manifests as raised yellow or off-white plaques up to 2 cm in diameter
Pseudomembranous colitis
Study of choice for Antibiotic associated colitis?
What’s another option?
PCR = study of choice
Another option is Enzyme Immunoassay (EIA), which requires two samples
For antiobiotic associated colitis, when is imaging warranted? What are we evaluating for?
When there’s evidence of fulminant disease. Used to evaluate for toxic megacolon, perforation, or other complications
contrast enhanced CT
What are some complications of fulminant antibiotic associated colitis?
Hemodynamic instability Hypercoagulability (from hypoalbuminemia( Respiratory failure Metabolic acidosis Toxic megacolon Bowel perf
What are general tx measures for antibiotic associated colitis (regardless of severity)?
Admission
***D/c offending antibiotic!
Infection control measures
Correct fluid/electrolyte disturbances
First line tx for MILD/MODERATE antibiotic associated colitis?
Metronidazole 500 mg PO TID x 10 days
alternate = vancomycin 125 mg PO QID x 10 days
What would you do if there’s no clinical improvement w/ metronidazole therapyin 5-7 days?
Switch to vancomycin
Why not just start w/ vancomycin?
COST and decrease in likelihood of abx resistance
Tx for SEVERE antibiotic associated colitis?
Vancomycin 125 mg PO QID x 10 days
Tx for FULMINANT antibiotic associated colitis?
Vancomycin 500 mg PO QID
AND
Metronidazole 500 mg IV q8 hrs
AND
Vancomycin PR 500 mg QID
AND EARLY CONSULTATION
A quarter of patients w/ abx associated colitis will relapse w/ 14 days…
What’s the tx for the FIRST relapse?
Repeat course of abx
What’s the tx for a subsequent relapse (i.e., third case) of antibiotic associated colitis?
7 WEEK taper of vancomycin
Consider probiotics/fecal transplant
Total or segmental colonic dilatation
Non obstructive
LARGER THAN 6 CM (must be assessed by rad)
Systemic toxicity
Toxic megacolon
complication of IBD but typically ulcerative colitis
Radiographic evidence of colonic distension (>6cm)
PLUS 3 of:
2a. Fever (100.4)
2b. Pulse (>120)
2c. Leukocytosis (>10,500)
2d. Anemia
PLUS 1 of:
3a. Dehydraion
3b. AMS
3c. Electrolyte abnormality
3d. HOTN
Toxic megacolon
Evidence req’d for toxic megacolon?
Radiographic evidence of colonic distension (>6cm)
PLUS 3 of:
2a. Fever (100.4)
2b. Pulse (>120)
2c. Leukocytosis (>10,500)
2d. Anemia
PLUS 1 of:
3a. Dehydraion
3b. AMS
3c. Electrolyte abnormality
3d. HOTN
Tx for toxic megacolon?
Reduce colonic distension
Correct fluid/electrolyte disturbances
Treat toxemia/precipitating factors
Surgical consult
Sac like protrusion of the colonic wall?
diverticulum
Most are asymptomatic (“incidental findings”)
Vary in size/number
Nearly universally present in sigmoid/descending colon
Pathogenesis related to increaed intraluminal pressure (low fiber/insufficient water intake)
Colonic diverticula
What is the diverticulosis?
Tx/work up?
Presence of diverticula (usually found incidentally/typically asymptomatic)
No specific tx or further work up is necessary (recommend increase in dietary fiber/water)
Diverticular bleeding is typically self-limited. However, pt may complain of what?
Painless hematochezia (blood that squirts into the toilet)
Typically no other ssx
Tx for diverticular bleeding?
With active bleeding, resuscitation/stabilization (CONSIDER UPPER GI BLEED) and endoscopy
Pts w/o active bleeding, refer for scope (colonoscopy)
Inflammation/perforation of a diverticulum (typically a micro-perforation and results in an intraabdominal infection). How’s the pt present?
Diverticulitis pt presents w/
abdominal pn/tenderness in LLQ
Fever
N/V
Diverticulitis PE?
Labs?
LLQ TTP (20% will have a mass)
Fever
Lab = leukocytosis (w/w/o +FOBT)
WHAT DO WE NOT GIVE A PT W/ DIVERTICULITIS?
NO ENDOSCOPY
Diagnostic imaging for diverticulitis?
Abd CT
but not always necessary in pts w/ mild dz, ie, mild TTP w/ no fever
Mild diverticulitis tx?
Type of abx?
Outpatient
Oral broad spectrum abx:
1. Metronidazole + Cipro
- Metronidazole + TMP-SMX
- Amoxicillin-Clavulanate
(7-10 days)
Clear liquid diet (advance as tolerated)
What disease/condition?
Clear liquid diet
Oral broad spectrum abx:
1. Metronidazole + Cipro
- Metronidazole + TMP-SMX
- Amoxicillin-Clavulanate
Diverticulitis
Criteria for INPATIENT mgmt of diverticulitis?
Complicated diverticulitis as seen on CT scan
Sepsis
High fever (>102)
Significant leukocytosis
Advanced age
Immunocompromise
Significant comorbidities
Unable to tolerate PO intake
Failure of outpatient mgmt
Complicated diverticulitis as seen on CT scan
Sepsis
High fever (>102)
Significant leukocytosis
Advanced age
Immunocompromise
Significant comorbidities
Unable to tolerate PO intake
Failure of outpatient mgmt
Diverticulitis that warrants inpatient mgmt
Severe/inpatient mgmt of diverticulitis?
NPO
IV broad-spectrum abx (Once inflammation is stabilized -> PO)
IV fluid/electrolytes
IV pn mgmt
Surgical consultation
When would you transition from IV to PO abx in severe diverticulitis?
Once inflammation is stabilized
Potential complications of diverticulitis?
Perforation
Abscess
Fistulization
Obstruction (from severe inflammation)
If a pt w/ diverticulits fails to improve after an abx regimen, what should be considered and obtained?
Consider complications, such as an abscess
Obtain CT if suspecting a complication
Ssx of obstruction w/o mechanical lesion?
Presence of bowel dilation on imaging
Acute colonic pseudo-obstruction (Ogilvie Syndrome)
When does acute colonic pseudo-obstruction occur?
Shortly after surgery (“postsurgical”)
Post-trauma
Medical inpatients (e.g., respiratory failure, MI, CHF)
Ssx of acute colonic pseudo obstruction?
Abd distension
Abd pn
Nausea/vomiting
Essentials of DX:
- severe abdominal distention
- Postoperative state or severe medical illness
- precipitated by electrolyte imbalances /meds
- Absent to mild abdominal pain; min tenderness
- massive dilation of cecum or R colon
What imaging might be used for ACPO?
??f/u to determine study of choice
Plain film shows colonic dilation (USUALLY confined to cecum/right hemicolon)
(CT can r/o mechanical obstruction if suspected due to malignancy, volvulus, or fecal impaction)
normal cecal size is 9 cm… cecal diameter greater than 10-12 cm is associated w/ increased risk of perforation!
Torsion of a segment of the alimentary tract is called?
What can it lead to?
Most common site?
Volvulus can lead to obstruciton
MOST COMMON SITE IS SIGMOID (can occur anywhere)
Insidious onset of progressive abd pn
Continuous/severe pn at presentation
Nausea
Abd distension
Vomiting
CONSTIPATION
Sigmoid volvulus
(ACPO aka Ogilvie is only absent to mild abdominal pain)
Toxic megacolon from IBD or C diff would have fever; dehydration, sig abdominal pain; leukocytosis; and diarrhea, which is often bloody (instead of constipation)
PE of sigmoid volvulus?
Distended abd w/ tympany to percussion
TTP
(lab tests typically unremarkable)
Imaging and tx for sigmoid volvulus?
Plain abd films
CT to r/o other etiologies
Tx is detorsion via flex sig
Protuberance extending into the lumen of the colon, that’s typically asympomatic… but may lead to?
Polyp… may lead to
Bleeding
Tenesmus
Obstruction
Two types of polyps?
Pedunculated (connected by thinner stalk)
Sessile
Four types of polyps?
- Mucosal adenomatous
- Mucosal serrated
- mucosal non-neoplastic
- Submucosal lesions
Most common polyp?
Description?
Adematous
Dysplastic by definition
May be tubular, villous, or tubulovillous
Display a lumen w/ serrated or stellate architecture
Serrated polyps (including hyperplastic polyps)
Type of non neoplastic polyps that has no clinical significance…
Includes hamartomas… which are?
Mucosal non-neoplastic
Hamartomas = benign tumor-like malformations made up of an abnormal mixture of cells/tissues
Create polypoid appearance of overlying mucosa
Submuscosal lesions
Bad to see on pathology report?
adenoma
dysplasia
(hyperplastic, not so bad)
Inherited disorder
Development of 100s+ of polyps
Develop polypls by 15
Development of cancer is inevitable (requires an eventual total colectomy)
ANnual colonoscopy requiered until colectomy
Familial Adenomatous Polyposis
Polyposis syndrome that presents w/ hamartomas and oral lesions
Peutz Jeghers Syndrome
Familial Juvenile Polyposis
type of hamartomatous Polyposis syndrome
increased risk of colon CA
Cowden disease
type of hamartomatous Polyposis syndrome
AKA Lynch Syndrome
Autosomal dominant condition
Increased risk of abdominal organ cancer
Use what for screening?
Hereditary Nonpolyposis Colon Cancer (HNPCC)
Bethesda Criteria
Colorectal cancer risks?
IBD
Smoking
Family Hx (first degree relatives)
Age (risk > after 45)
DIet high in fat and red meat
Cancer lesions maybe present for years before symptoms begin. So?
We implement prevention and detection tests
Colorectal CA prevention tests?
Colonoscopy
Flex Sig
CT colonography
Colorectal CA DETECTION tests?
Fecal Immunochemical Test
Hemoccult SENSA
Fecal DNA
What constitutes a high risk CRC pt?
Single first degree relative w/ CRC or advanced adenoma diagnosed at age > 60
Two first degree relatives w/ CRC adenomas
What is the recommended screening for high risk patients?
Colonoscopy every 5 years beginning at age 40 years or 10 years younger than age at diagnosis of the youngest affected relative
Used for prognosis AFTER diagnosis
(NOT a screening test)
USed as a marker for recurrence
Carcinoembryonic Antigen (CEA)
Colorectal cancer of the right colon… ssx?
Iron deficiency anemia
Weakness/fatigue
CRC of the L colon… ssx?
Change in bowel habits
Blood streaked stool
Obstructive symptoms
CRC in the rectum… ssx?
Tenesmus
Hematochezia
Urgency
Decrease in caliber of stool (“ribbon stool”)
What are the signs of advanced CRC?
Complete obstruction (“apple core” lesion)
Wt loss
Fever, chills, night sweat
Work up for CRC?
FOBT (guiac or FIT)
CBC
CMP
UA
Colonscopy
Tx for CRC?
Surgical resection (full/partial colectomy)
Chemotherapy
Radiotherapy
CRC prognosis?
Stage 1 = best
Stage 4 = worst
